In recent years, high-performance display devices such as a large screen television have become widely used. An image quality of the display devices is highly affected by uneven brightness and uneven color in a displayed image (hereinafter, the uneven brightness and the uneven color may be collectively referred to as “unevenness”), and thus correction of unevenness is required.
Patent Document 1 discloses a technology for correcting unevenness. According to the technology, a display panel on which an evaluation image is displayed is captured with a camera to obtain a photographic data, and then a brightness distribution and/or a color distribution of the display panel is/are extracted from the photographic data. Then, the extracted brightness distribution and/or the extracted color distribution is/are corrected based on an ideal brightness distribution and/or an ideal color distribution. In the brightness distribution and/or the color distribution, the ideal brightness distribution and/or the ideal color distribution include(s) “non-uniform distribution of display light intensity” that is barely-noticeable to the human eye. According to the technology disclosed in Patent Document 1, the brightness distribution and/or the color distribution is/are corrected based on the ideal brightness distribution and/or the ideal color distribution. This reduces deterioration of brightness and gradation characteristics of the entire display area compared with the case that the brightness distribution and/or the color distribution of the display panel is/are corrected to be uniform.